Zotero fails to capture metadata

[Dan Scott]

* Evergreen 3.1.2

Symptom: Zotero successfully captures rich data from some catalogue records, but falls back to just a regular web page snapshot for others.

Cause: For some records, biblio.record_entry.tcn_source field is an empty string (''), which results in the MARCXML that is generated to have an empty 901 $b subfield (<subfield code="b" />), which causes the Zotero MARCXML translator to error out.

The reason the tcn_source for some records are empty strings is because the Perl record import code sets the value to an empty string if it can't find any other source (e.g. OCLC number) to avoid causing a Perl warning in the logger info call. The empty string then gets passed to the database, meaning that it satisfies the non-NULL constraint and doesn't invoke the default value of 'AUTOGEN'.

The simple fix is to not set the value of the tcn_source field in the bib record object if the corresponding variable evaluates to false (such as if it's an empty string).

[Dan Scott (denials)]

A branch with one of the larger ratios of commit description to actual patch length is available in the working repository at user/dbs/lp1776954_avoid_empty_string_tcn_source (http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/dbs/lp1776954_avoid_empty_string_tcn_source).

[Chris Sharp (chrissharp123)]

Seems a big shame this took so long to make it in. Committed to master, rel_3_4, and rel_3_5 with a commit adding release notes about the potential need to update existing records with blank TCN Source.

Thanks, Dan!